Various devices to dilute or otherwise protect against smoke have over the years been proposed and are documented in the patent literature. However, it appears the inventors were not cognizant of the venturi effect which tends to entrain surrounding gas and thereby rendering the various proposed inventions non functioning or very inefficient for their intended purpose. This is also evidenced in the current technology in use particularly in aircraft cockpit for smoke evacuation purposes where dilution by outside air is the means of attempting to cope with dense continuous smoke in the cockpit window in severe circumstances. Neither of these procedures work to eliminate a continuous dense smoke problem in the cockpit. Opening the window has little or no effect because of the aerodynamics surrounding the fuselage where the windows are located and the small controllable air nozzles merely entrain the surrounding smoke and mix it with the airstream thereby having little or no effect during emergencies where the smoke cannot be stopped.
The present invention overcomes these fundamental deficiencies and in addition provides added advantages as disclosed below.
It is noteworthy to observe that the problem of dense vision impairing smoke is particularity acute in aircraft and there is a long history of smoke accidents where pilots have been unable to see to safely control and land the aircraft. Likewise, although the historical record may not be as catastrophic as in the aviation industry, a similar problem exists on submarines where operators need to be able to see to turn off reactors and otherwise manipulate controls read instruments to control a fire/smoke emergency. U.S. Pat. No. 4,832,287 issued to Werjefelt addresses this safety dilemma and does provide vision for pilots and other operators regardless of smoke density. However, depending on what criteria may be applied, the present invention may prove to be a substantial improvement in that it solves the problem in a quite different way with less cumbersome paraphernalia for the users to contend with. While it may not provide as guaranteed a protection of vision as that described in the Werjefelt patent, it may in certain applications provide a very satisfactory level of safety for the purpose of pilot or other operator vision assurance.
It is an object of the present invention to provide means by which to evacuate smoke from a desired area for the purpose of obtaining visibility, which otherwise would be impaired by the presence of dense continuous smoke in an enclosed space.
It is another object of the present invention to provide a device that when connected to an appropriate supply of breathable air, while also providing visibility, will at the same time provide a respirable environment in the area from which smoke is being evacuated by the device.
It is still another object of the present invention to replace goggles which are used to protect the eyes from the lacrimatory effects of smoke and toxic gases and fumes while at the same time also replacing a gas mask or smoke hood or oxygen mask which is the present means of protecting respiration of people who are confined in an enclosed area where smoke and lethal fumes may be present in an emergency.
It is another object of the present invention to replace or improve upon recent technological advances designed to ensure vision of instruments and controls for operators in enclosed areas where dense smoke may otherwise severely or completely inhibit such vision.
The invention can be in the form of a small portable device or it can be built into a structure as a fixed stationary device system. The device may incorporate compressed gas supplies, filtering means or external air/gas supplies as suitable for the protection means for providing protection against decompression for airline passengers and crew without the need for the conventional xe2x80x9clittle yellow cupxe2x80x9d commonly found on jet liners to provide supplementary oxygen for passengers in the event of decompression. Again the invention, regardless of its intended function i.e for visibility, for protective breathing for eye protection or for decompression protection can be in the form of a small portable installation/system incorporating gaseous generating sources and/or fixed pipes or hoses to provide appropriately pressurized supplies of air or oxygen.
Moreover, the invention also has applications underwater for the purpose of aiding divers doing underwater work in murky waters, where it can be used to evacuate or displace the murky water to provide clear visibility for divers.
In summary, the present invention provides a smoke evacuation device comprising a nozzle for connection to a source of clean air supply, the nozzle being adapted to vent clean air supply in all available directions in space therefrom to provide a volume of space with clean air in the proximity of the nozzle, thereby providing visibility and breathable air to the user. The nozzle is adapted to minimize entrainment of the surrounding smoke into the volume.
The present invention further provides a protective breathing device, comprising a source of breathable gas; a nozzle for connection to the source of breathable gas, the nozzle being adapted to vent the gas in all available directions in space therefrom to provide a volume of the breathable gas and clear visibility in the proximity of the nozzle; and the nozzle is adapted to minimize entrainment of the surrounding smoke into the volume.
The present invention still provides a device for providing supplementary oxygen for protection against decompression, comprising a source of oxygen; and a nozzle for connection to the source of oxygen, the nozzle being adapted to vent the oxygen in all available directions in space therefrom to provide a volume of oxygen and clear visibility in the proximity of the nozzle.
The present invention also provides a device for providing visibility for divers, comprising a nozzle for connection to a source of clear water supply, the nozzle being adapted to vent the clear water supply in all available directions in space therefrom to provide a volume of space with clear water in the proximity of the nozzle, thereby providing visibility to the user; and the nozzle is adapted to minimize entrainment of the surrounding murky water into the volume.
The present invention further provides a device for providing clean air in a desired volume/area free of contaminants, comprising a nozzle for connection to a source of clean air supply, the nozzle being adapted to vent the clean air supply in all available directions in space therefrom to provide a volume/area free of contaminants in the proximity of the nozzle; and the nozzle is adapted to minimize entrainment of the surrounding contaminated air into the volume/area.
The present invention also provides a device for providing a desired gas in a certain volume/area, comprising a nozzle for connection to a source of desired gas, the nozzle being adapted to vent the desired gas in all available directions in space therefrom to provide a volume/area containing the gas in the proximity of the nozzle; and the nozzle is adapted to minimize entrainment of the surrounding air into the volume/area.
These and other objects of the present invention will become apparent from the following detailed description.
The essence of the present invention rests in the function of the xe2x80x9cnozzle(s)xe2x80x9d in that the gaseous flow from the nozzle used to evacuate the smoke outside of the nozzle is so designed that the flow of gas is xe2x80x9comnidirectionalxe2x80x9d in all possible directions from the nozzle to the surrounding space. By providing an omnidirectional flow one is able to overcome the deficiencies of the prior art, namely the entrainment, of the surrounding smoke into the airstream which is used for smoke evacuation or smoke displacement purposes. It will be readily apparent to anybody reasonably versed in the art that the omnidirectional flow can be accomplished by many different means such as, but not limited to, appropriately designed holes, slits, baffles, sintered/porous materials and/or otherwise permeable materials depending on flow rate, pressures involved of the gas supply etc.
For instance a sintered material may be suitable to use where very high gas supply pressures are used. The sintered material would then function to release the gas in appropriate directions and at an appropriate rate to accomplish the intended function. Thus this invention specifically provides for means to eliminate the long-standing problem of entrainment of a surrounding gas (smoke) thereby allowing a certain volume within an enclosed area to be free of undesirable gas i.e. toxic smoke, lethal fumes and vision impairing contaminants or in the case of underwater applications, murky water. Moreover, the invention can also provide for clean air in contaminated environments, for example in operating rooms, where it is desirable to have a clean volume of air, free of microbes and the like, in the immediate area surrounding an incision. Or, likewise it can be used to provide a clean breathing environment for persons where the environment is otherwise contaminated by microbes, virus or the like. The invention can also be useful in ordinary environments, for instance where smoking is permitted, but non-smokers in the same area would like to have fresh air surrounding them.
By way of simple description, an xe2x80x9comnidirectionalxe2x80x9d nozzle placed at the end of a pipe or hose would therefore have a flow in a spherical direction inclusive of the direction down towards and along the pipe or hose feeding the omnidirectional nozzle. The flow along the pipe or hose is critical in order to eliminate entrainment.
In the case where an omnidirectional nozzle is used on a flat surface, for instance an instrument panel in a cockpit, the flow would be that of half a sphere, in other words an omnidirectional nozzle was placed in the corner of an enclosure i.e. in the corner between two walls and ceiling in a room, the flow therefrom would be that of a quarter of intervening space. Thus, in all these cases, eliminating entrainment into the airstream used for smoke evacuation or dilution of the surrounding gas. At some point entrainment will occur and there will be a limit to the extent of the effective outward flow from the nozzle, after which mixing and entrainment will occur.